Vascular access channel and methods

ABSTRACT

An embodiment includes a vascular port comprising: first and second portions that are not monolithic with each other; wherein: (a)(i) the first portion includes a first arcuate surface to contour to a first portion of a vessel and the second portion includes a second arcuate surface to contour to a second portion of the vessel; (a)(ii) the first and second portions couple to one another around the vessel when implanted to form a central chamber that houses the vessel; (a)(iii) the first portion includes a port that includes a funnel with a funnel surface that narrows as the funnel surface approaches the central chamber; (a)(iv) the central chamber includes a central longitudinal axis and the funnel includes a central vertical axis that is orthogonal to the longitudinal axis; (a)(v) the second portion includes a hardened, non-compliant surface that intersects the vertical axis.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/157,589 filed on May 6, 2015 and entitled “Ported Vascular AccessChannel,” the content of which is hereby incorporated by reference.

TECHNICAL FIELD

Embodiments of the invention are in the field of medical devices and, inparticular, vascular access methods and devices.

BACKGROUND

The kidneys constantly filter blood, removing toxic substances, bodilyfluids, and waste. Patients with decreased kidney function often requiredialysis machines to serve as artificial kidneys to clean the blood. Endstage renal disease (ESRD) can be caused by a variety of conditionsincluding diabetes, hypertension, glomerulonephritis, polycystickidneys, and urological disease. As of 2010, approximately $40 billiondollars are spent annually in the United States on ESRD treatment, witha significant portion going towards dialysis treatment. Of the 550,000people with ESRD in the US, approximately 400,000 are on some form ofdialysis.

There are several vascular access methods currently utilized forhemodialysis. The most immediate form of access is a temporary duallumen catheter placed through a vein, such as the jugular or subclavian.The catheter tip is often positioned in the superior vena cava or theright atrium of the heart to allow for the high flow rates needed forhemodialysis (at least 200 mL/min). This method provides immediateaccess when needed. However, catheters frequently cause problems in theveins they are fed through. Infection and thrombosis leading tosubsequent scarring and occlusion of the vessels can occur.

An arteriovenous (AV) anastomosis can provide an alternative, long termsolution using grafts or fistulas. Both the graft and fistula methodsare surgical techniques often employed in the arms. Native peripheralarteries and veins are generally too narrow to accommodate the largeflow rates required for hemodialysis. These techniques provide a way toenlarge a vein to a more appropriate diameter. In the case of an AVgraft, an artificial vessel (often made of polytetrafluoroethylene, orPTFE) is tunneled through the subcutaneous tissues between an artery anda vein. After healing, the graft will provide a site for repeatabledialysis access. Grafts are not a preferred technique by Medicarehowever because they have a shorter lifespan when compared toarteriovenous fistulas, mostly due to infection risk from foreignmaterial, the high-frequency of clot formation within the graft, orpossibly the weakening of the graft due to multiple punctures.

AV fistulas are the current preferred method for hemodialysis access.Since they are created from the body's own tissue, there is less risk ofinfection. In addition, the fistulas have an increased long term patencyrate. Despite these advantages, AV fistulas still have many drawbacks,including a prolonged period of maturation prior to use, poor maturationof the draining vein (it may not dilate to an adequate diameter toenable access), diminished circulation distal to the site (arterialsteal), and difficulty cannulating the vein for dialysis. Fistula wallscan weaken over time, becoming sites of aneurysms that can be a focusfor thrombosis and infection, and therefore failure. The indications ofa usable dialysis fistula are 1) sufficient diameter of the vein, 2)sufficient flow through the vein, and 3) an adequately superficiallocation under the patient's skin. If these conditions are not met, theanastomosis is considered immature. Early-stage fistula failure isdefined as a fistula that never fully develops or fails within 3 monthsof its creation. A common cause of early-stage fistula failure is astenosis in the vein, often located at the anastomosis. Causes oflate-stage fistula failure (after 3 months) are difficulty cannulatingthe fistula, low flow rates, and thrombosis. It is clear that newmethods are required which can eliminate or reduce the problemsassociated with current techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of embodiments of the present invention willbecome apparent from the appended claims, the following detaileddescription of one or more example embodiments, and the correspondingfigures. Where considered appropriate, reference labels have beenrepeated among the figures to indicate corresponding or analogouselements.

FIG. 1: A ported vascular access channel with biodegradable matrixscaffold in an embodiment.

FIG. 2: A ported vascular access channel with biodegradable matrixscaffold removed in an embodiment.

FIG. 3: An embodiment in which needle wells resemble a “trough”.

FIG. 4: An exploded view of a ported vascular access channel in anembodiment.

FIG. 5: A cross-section view depicting a biodegradable matrix scaffoldand rigid back wall in an embodiment.

FIG. 6: An embodiment depicting rudders, suture points, and flanges.

FIGS. 7(a), 7(b), 7(c): A concentric stent within a graft wall lockingthe graft in place within a port in an embodiment.

FIG. 8: A ported vascular access channel with graft implanted inpatient's arm in an embodiment.

FIG. 9: A “u”-shaped port configuration in an embodiment.

FIG. 10: A ported vascular access channel with catheter in anembodiment.

FIG. 11: A ported vascular access channel with catheter implanted inpatient's thorax in an embodiment.

FIG. 12: A tunneled contour with prongs in an embodiment.

FIG. 13: A cross-section of top face portion showing recess forbioactive matrix scaffold in an embodiment.

FIG. 14: A sheet of bioactive matrix scaffolding in an embodiment.

FIG. 15: A fish-mouth shape of a trough in an embodiment.

FIG. 16: A funnel accommodating two directionally opposed needles in anembodiment

DETAILED DESCRIPTION

In the following description, numerous specific details are set forthbut embodiments of the invention may be practiced without these specificdetails. Well-known structures and techniques have not been shown indetail to avoid obscuring an understanding of this description. “Anembodiment”, “various embodiments” and the like indicate embodiment(s)so described may include particular features, structures, orcharacteristics, but not every embodiment necessarily includes theparticular features, structures, or characteristics. Some embodimentsmay have some, all, or none of the features described for otherembodiments. “First”, “second”, “third” and the like describe a commonobject and indicate different instances of like objects are beingreferred to. Such adjectives do not imply objects so described must bein a given sequence, either temporally, spatially, in ranking, or in anyother manner.

There is a growing need to replace current hemodialysis accesstechniques with methods that allow for earlier use of long term vascularaccess and that minimize the chances of complications and failure of theaccess. Current methods can take time to “mature” and become usable, andcan become blocked or unusable over time. However, embodiments describedherein provide, for example, a long term access device that (a) providesa viable means for dialysis, (b) is simple to locate and access by thedialysis technician, (c) provides improved accessibility throughout thelifespan of the device, and (d) is usable shortly after surgery.

Embodiments described herein offer improvements including, but notlimited to, the following. First, in an embodiment a port is assembledfrom multiple pieces: a bottom face, a top face featuring a centralopening (termed the “needle well”), and a bioactive matrix scaffoldsituated within the needle well. These pieces shall join to produce aport capable of encasing a vessel to provide blood access. Second, in anembodiment the port is assembled without the use of a bioactive matrixscaffold and comprises the top and bottom faces. Third, in an embodimenta bioactive matrix scaffolding is included within needle well(s). Thisprovides an immediate means of sealing the port after it is punctured,allowing for a faster turnaround time between implantation and use. Thebioactive matrix scaffold may be punctured and will provide a substrateto initiate hemostasis, and over time will encourage infiltration of thebody's own vascularized, fibrous tissues. A barrier of natural tissuewill resist infection better than a typical silicone or urethane plugand encourage hemostasis after puncture. The bioactive matrix scaffoldmay either be permanent or degradable. Fourth, in an embodiment the portis easier to locate under the patient's skin than other subcutaneousgrafts or fistulae which are more compliant and whose locations may bedifficult to approximate by palpation. It also serves to guide theneedle into the proper location within the lumen, eliminating some ofthe human error involved in obtaining proper vascular access. The portalso prevents a needle from puncturing through the back wall of thevessel (e.g., graft), which is a common cause for blood loss into thesubcutaneous tissue and subsequent hematoma formation (a complicationthat can result in lost access and the need for expensive intervention).Fifth, an embodiment adapts the port concept to a catheter, such that asubcutaneous catheter has the following advantages: (a) the bioactivematrix scaffold barrier encourages vascular tissue ingrowth (whichallows infiltration into the device by lymphocytes to reduce infection),(b) the catheter would not be exposed to pathogens on the skin'ssurface, lowering infection risk, and (c) the catheter would retain theimmediate usability of other vascular access catheters that arecurrently used for functions including hemodialysis, chemotherapy, andthe like. Sixth, an embodiment includes angled side-entry points thatallow simplified removal of thrombi from the graft by an interventionalphysician via a catheter or guide wire.

An embodiment creates a new form of vascular access to improve orreplace existing methods. The embodiment facilitates access to a bloodvessel or graft via a port apparatus which allows consistentendovascular access into the lumen of the vessel via needles inserteddirectly into the port. The port apparatus provides structural support,decreasing the amount of trauma incurred to the vessel wall or graft anddiminishing the subsequent scarring and stenosis. In an embodiment, abioactive matrix scaffold made of some combination of natural tissueand/or synthetic polymer prevents bleeding from the vessel and greatlydecreases the maturation time of the fistula or graft. The port islocated directly under the skin, enabling easy access to the vessel andlimiting the risk of infection by utilizing the skin as a naturalbarrier to pathogens. This also addresses the current challenge oflocating a viable access point; for instance, many dialysis patients areobese, and their AV fistulas may be hard to find and puncturesuccessfully. Alternatively, due to collateral veins some fistulas nevercontain enough blood to dilate perceptibly. Because vascular access mustoften be performed multiple times per week, there is little time forskin to heal between treatments. The needle wells guide the needle downinto the vessel while providing a greater surface area for needlepuncture. This enables vascular access technicians to puncture indifferent locations along the skin's surface, thus preventing skinbreakdown and giving each site a chance to heal. In addition,technicians are able to advance the needles at different angles becausethe port directs the needle's path directly into the vessel lumen. Therigid back wall of the port functions as a stopping point for theneedle, thereby preventing through-and-through punctures. Access istherefore simplified, enabling even an inexperienced person to accessthe vessel, which may result in an increased use of home-based vascularaccess treatments and a new level of independence for patients,including dialysis patients who must often visit a dialysis clinic threetimes per week. Angled side-entry points adjacent to the needle wellswill function as entry sites for wires/catheters that interventionalphysicians use to clean thrombi out of clotted grafts thus simplifyingthis procedure. Though embodiments have great utility for dialysispatients, such embodiments have capabilities as a long-term and reliableblood-access method and are therefore suitable for use in plasmapheresisor as a chemotherapy or drug-delivery system for patients with chronicillnesses that require frequent infusions of nutrients, antibiotics,clotting factors, parenteral nutrition, or other injectable therapies.

As used herein the term “ported vascular access channel” is meant torefer to the compartment through which blood or other fluid (e.g.,biological fluid) may flow in addition to the accompanying features asdescribed herein. That fluid compartment may include a natural vessel, asynthetic graft, catheter with subcutaneous port, and the like.

An embodiment comprises a port 5 surrounding a blood vessel or graft orcatheter or other blood access channel to be used for permanent bloodaccess (FIG. 1). The port may be fabricated from a biocompatibleplastic, metal, or ceramic. Such materials include, for example,titanium, Poly Ether Ether Ketone (PEEK), aluminum oxide, and the like.

In an embodiment the needle puncture site(s) is palpable from thesurface of the patient's skin and is composed of one or more wells 2(FIG. 2). The needle wells are cavities leading from the port's outersurface to the inner lumen of the vessel 4 and are contoured such thatthe needle 1 is guided directly into the inner lumen. They may befunnel-shaped in order to increase the total skin surface area that maybe punctured by the needle to allow the skin a chance to heal. Apreferred embodiment of the wells may resemble a trough 18 (FIG. 3) thatincludes room for many puncture sites down the length of the port. Theadvantage of this guided-needle entry system is the ease of access intothe vessel. Fewer attempts will be necessary to achieve a successfulpuncture, improving patient comfort, lowering risk of infection, andsparing the vessel from increased trauma and scarring. Additionally, asimplified vascular access method may enable home dialysis.

In an embodiment the bottom face of the port 9 is rigid to preventrupture of the vessel's back wall 10 by the needle. This is necessaryfor preventing loss of blood into the extraluminal space where it maycause a hematoma and block access into the vessel. In an embodiment thebottom face of the port may have a layer of softer material in which toembed the needle and assist in immobilizing it. This softer material mayconsist of, but is not limited to, a low-density silicone sheet or othersoft plastic. The very back layer of the port may be formed from ahigh-hardness material such as an alumina ceramic or metal that resistsdamage by the needle, which is made of a stainless steel in anembodiment.

An embodiment of the port (FIG. 4) comprises multiple pieces that areassembled in differing fashions. An embodiment may include a sleeve 6and needle well insert 7 which may be assembled from separate materialsin order to maximize useful properties of each material. The needle wellinsert may be formed from a high-hardness material such as a titaniumalloy or alumina ceramic in order to minimize wear debris created byfriction between the well and the needle. In addition, both of thesematerials are very corrosion-resistant and have an excellent trackrecord in the field of orthopedic implants.

In an embodiment the needle well(s) enable a method of preventing bloodfrom leaking out of the port immediately following vascular access andwhen the device is not in use. An embodiment involves filling the wellwith a bioactive matrix scaffold 8 (FIGS. 4 and 5) that serves as aninitial impediment to blood loss by stimulating hemostasis and, overtime, encouraging vascular tissue ingrowth. This will transform thebioactive matrix scaffold into a self-healing barrier. This tissue hasthe ability to aid in clot formation to stop bleeding following vascularaccess and is not as susceptible to developing the type of latentbiofilm infection that is often associated with implanted materials.Bacteria introduced into the port can be eradicated by the body's ownimmune system, improving the device's long-term integrity andusefulness. In addition to or instead of the biodegradable matrixscaffold, the needle well(s) may contain a bactericidal component suchas silver nitrate that could aid in preventing the development of abiofilm within the well. The presence of the bioactive matrix scaffoldwithin the well should also decrease the waiting period before thedevice can be used to access blood. Current arteriovenous grafts requireseveral weeks before they can be accessed, and fistulas may requiremonths. A ported vascular access channel with a hemostatic bioactivematrix scaffold is a solution that is usable much sooner followingimplantation, an important option for acute renal failure patients.

Though the needle wells are intended to maximize the surface area thatcan be punctured by a needle, the presence of a barrier of bioactivematerial/natural tissue within the port's needle wells make itwell-suited for the “buttonhole technique.” In the buttonhole technique,the needle is inserted by the technician at the exact same point foreach treatment. In fistulas this method has shown to be effective indecreasing patient discomfort, decreasing bruising, lowering infectionrates, and enabling home dialysis. With a barrier of natural,self-healing tissue within the port, the use of the buttonhole techniquecould afford these same advantages to ported grafts or catheters.

A number of materials and additives exist which may serve asconstituents of the bioactive matrix scaffold 8, which may comprise anynumber of biocompatible natural or synthetic materials, includingwithout limitation, polymer foams, poly ethylene glycol (PEG) hydrogels,polyglycolic acid (PGA), polylactic acid (PLA), poly(lactic-co-glycolicacid) (PLGA), glutaraldehyde adhesives, fibrin sealants, cyanoacrylates,collagenous compounds, electrospun fabrics, decellularized extracellularmatrix, or any other biocompatible material, degradable or not, thatwill encourage the formation of vascularized tissues. The bioactivematrix scaffold may either be inserted at the time of manufacture, oralternatively at the time of implantation, whichever is most expedientdepending on the desired material. The interfaces between the variousparts of the device may be filled with cyanoacrylates or otherspace-filling gels/foams (e.g., a polyurethane shape memory polymerfoam)/adhesives to prevent potential spaces from harboring bacteria, orin addition/alternatively the interfaces may be composed of bactericidalmaterials such as silver-doped ceramic.

In an embodiment a material for use as the bioactive matrix scaffold ispolyurethane urea foam, which has demonstrated excellent vascularingrowth in experiment. This material may be formed separately and lateradhered to the port, or instead may be cured within the port. Anembodiment includes a port material with large-diameter open pores(e.g., open cell polyurethane foam). As a result, the polyurethane ureapolymer can infiltrate and anchor itself within the cells during curing.In this method, vascular tissue can infiltrate the entire implant, withthe port material serving as a rigid “skeleton” that guides the needlesafely into the lumen of the vessel.

An embodiment includes a method of sealing the ported vascular accesschannel. The method utilizes a bioactive matrix scaffold that isgradually replaced with biological tissue. However, other embodimentsuse methods of sealing the channel and may also include some sort ofpermanent plastic rubber membrane or mechanical valve. An embodimentincludes no method of sealing the port, instead allowing thesubcutaneous tissues to fill the needle wells naturally. This processmay be aided by specific port materials, certain port structures, andoptimized port surface coating. An embodiment without the bioactivematrix scaffold comprises a titanium alloy port composed of a meshworkof large, open pores that allow excellent tissue infiltration andadhesion. In an embodiment pores are formed from nanotubes that fostertissue ingrowth and may further hinder bacterial growth. This enablesnot only the needle well, but the entire device, to be infiltrated bynatural tissues, improving anchoring and eliminating spaces that mayharbor bacteria. Such a structure is producible by powder metallurgy.Titanium and its alloys are naturally extremely biocompatible as theynaturally produce an oxidized layer of TiO2 on their surface which isvery stable at physiologic pH. In addition, processes have beendescribed to further improve Titanium's biocompatibility, including ananodization process which forms surface TiO2 nanotubes that improvetissue adhesion, and the “sol-gel” technique which produces layers ofceramic over the titanium, including the SiO2-based “bioglass” 45s5which is known to encourage excellent tissue growth.

Attempts to puncture current arteriovenous fistulas are complicated bythe pliability of these vessels, as they often collapse rather thanallow a needle to pierce them successfully. However, in an embodimentthe port provides radial support to the vessel wall and holds it openduring the needle's entry. This may be accomplished through surfacefinishes or coatings within the channel of the port that encourage softtissue attachment between the port and the vessel wall. An embodimentincludes a bioactive matrix scaffold which extends from the needle wellinto the port channel and surrounds the vessel to stimulate thisattachment (FIG. 4, area 6). An embodiment includes the use of anadhesive applied within the port channel, such as a cyanoacrylate glue,which results in adherence of the vessel wall to the surface of the portchannel. Alternately, in an embodiment in which the port surrounds anartificial vessel such as a PTFE graft, patency can be assured via aconcentric support 14 embedded into the graft wall 15 (FIG. 7).Application of a radial force to the vessel wall also prevents“pseudoaneurysms,” which form when blood leaks into the interstitiumadjacent to a damaged vessel and can end up sealing off the vessel andpreventing access. This feature reduces damage to the vessel, preventsleaking, and disallows the “mass effect” of a growing hematoma toocclude the vessel. Such a configuration forces the vessel to maintainpatency by disallowing the formation of aneurysms, pseudoaneurysms, orocclusions caused by external pressure.

As seen in FIG. 12, an embodiment includes a method of constructing thedevice as follows. A port, which comprises a bottom face 122 and a topface 121, where the top face contains a needle well (the central opening126), may be manufactured out of titanium or titanium alloys such asTi6Al4V via powder metallurgy or other process to bestow the port with ameshwork of pores or channels of any size. These pores may be varied insize on the outer surfaces of the device to encourage prolific tissueingrowth, and with additional pores on the surface of the trough orfunnel (2) and bottom face 123 (e.g., pores that are small enough toprevent passage of a needle). The top and bottom faces will encircle anarteriovenous fistula, though they may or may not make direct contactwith one another and instead leave a small gap between them. Forexample, portions 121 and 122 may not fit flush against each other whenassembled during implant.

In an embodiment, within the meshwork structure on the top and bottomfaces are opposing suture holes 12 into which a resorbable suture may beplaced by the surgeon in order to approximate the two faces. By usingresorbable sutures and allowing for a gap (not shown in FIG. 6 andpresent in some embodiments of FIG. 6 but not others) to exist, thepossibility that a biofilm might form between the two faces isdiminished, and the vessel retains its natural compliance, which isnecessary should the vessel dilate or require balloon angioplasty, or ifproliferating tissue begins to narrow the vessel's lumen. Into this portmay be formed the bioactive matrix scaffold consisting of thepolyurethane urea foam as described above.

In an embodiment the device utilizes top and bottom faces 121, 122 (FIG.12) which are approximated by prongs 77 on the bottom face (and/or topface). The prongs fit into corresponding holes on the opposing face butdo not fasten the faces flush together. This allows for expansion of thecenter channel and retains the vessel or fistula's natural compliancewhile preventing shear stress at the interface between the top andbottom faces. In an embodiment the device narrows on its ends to allowfor “tunneling” through tissue, and it may feature a roughened or poroussurface which is optimized for tissue adhesion. For example, a tissueingrowth promoting surface may have a texture provided by compaction andsintering of metallic beads (e.g., titanium beads) or powders onto theport. In other embodiments the surface may be formed by machining,sandblasting, laser etching, and/or injection molding. Within the topface is a recess 124 (FIGS. 12, 13) into which a sheet of the bioactivematrix scaffolding material 88 (FIG. 14) is inserted. The scaffoldmaterial may be subject to deformation as it is populated withcontractile connective tissue; to maintain its desired geometry thescaffold may be anchored by a ductile retention ring that can be fedthrough the scaffold, or by extending the length of the prongs 77 on thebottom face 122 such that they pierce the scaffold once the device isassembled around the vessel. The trough on the top face of the devicemay have an irregular “fish-mouth” shape 99 (FIG. 15), being narrower onits ends and wider at its center, to allow two dialysis needles to crossside-by-side while engaged within the trough.

An embodiment includes a method of constructing the invention for usewith a synthetic vascular graft. A vascular graft, which may be made ofexpanded polytetrafluoroethylene (ePTFE) material, is surrounded by aconcentric support or stent 14 of nitinol or other rigid material whichis then encapsulated by an additional layer of ePTFE 15 (FIG. 7). Thestent provides the graft with radial strength during needle puncture aswell as a larger profile with which to lock into place within the port 5(FIG. 4). In an embodiment, the port, made of Poly Ether Ether Ketone(PEEK) or one of any number of biocompatible materials, comprises asleeve with a rigid back wall that fits around the graft, concentricwith the rigid stent, locking the stent in place within the sleeve 6. Aneedle well insert 7 comprising a high-hardness material such as aceramic or titanium will lock into the top face of the sleeve 6 toprovide a surface that will identify the location of the graft beneaththe skin, guide the needles into the lumen 4 of the graft, and resistwear debris from shear stresses applied by the needle. The top surfaceof the needle well insert may be contoured 17 so as to help identify theappropriate location to insert the needles (FIG. 2). Within the wellsthemselves is biodegradable matrix scaffold 8, which may comprise apolyurethane urea foam or any number of well-known biocompatible naturalor synthetic materials as previously described.

An embodiment includes a method of adhering the port to the graftmaterial as follows. The graft is fed through a channel down the longaxis of the port and fastened to the port with a cyanoacrylate and/orfibrin adhesive. The needle well insert is included, and thebiodegradable matrix scaffold as described above may be placed withinthe needle well insert at this time or injected into the wells duringthe implantation surgery. As before, the interfaces between the variousmaterials may be filled with cyanoacrylates or epoxies to preventpotential spaces from harboring bacteria, and/or the interfaces may becomposed of bactericidal materials such as silver-doped ceramic.

An embodiment includes an alternative method of adhering the port to thegraft material as follows. The port itself is assembled into one solidpiece, including the needle well insert. At the proximal and distal endsof the port are flanges 13 (FIG. 6) onto which the graft tubing mayslide concentrically, eliminating the need to adhere the graft materialto the inside of the port. In this embodiment the inner channel of theport may receive various treatments to improve hemocompatibility, suchas heparin or DLC coatings, which have been shown to reduce clotting.

An embodiment includes a method as follows. After using standardsurgical technique for the creation of an AV fistula, the port,comprising a top and bottom face, is placed circumferentially around thefistula and the two faces are approximated using resorbable sutures. Theport is oriented such that the top face is parallel with the surface ofthe patient's skin. The fistula may be mobilized in order to place theport at an appropriate depth such that it can be seen/palpated beneaththe skin. The resorbable sutures may also be used to anchor the port inthis position while the patient's own tissue begins to make itsattachments to the port.

In an embodiment, a similar method can be employed to install theimplant around an existing vessel. A port which separates into twosections, a back plate and a front plate or two symmetrical side plates,is fastened around an existing graft, arteriovenous fistula, or othervessel from which it is desirable to access blood. This may be done toenclose an aneurysm and prevent it from bursting or to simplify thelocalization of hard-to-find vessels.

An embodiment includes a method as follows. Using standard surgicaltechnique for the creation of an arteriovenous anastomosis withsynthetic graft material, the graft and attached port are mobilizedunder the patient's skin such that the top of the needle well insertfaces outwards to allow for needle access. Unlike typical arteriovenousgrafts, which are usually quite long so as to distribute damage fromneedles, the port will be the sole entry point into the lumen, andexcessive graft length will therefore be unneeded. This means the amountof implanted foreign material can be reduced, and with it the risk ofclotting and infection. Though kinks were a cause for concern in priorgrafts, the majority of the material in these grafts will not bepunctured, and therefore a thicker/stiffer material can be used toprovide additional stiffness and reduce the risk of kinks, especially atthe junctions between the compliant graft and the rigid port.

Vessel length and resistance are proportional; for instance, a ⅓reduction in graft length generally results in a ⅓ reduction in graftresistance and therefore an increase in blood flow, which may or may notbe desired. To combat this reduction in resistance, the graft diametercan be decreased, as resistance is proportional to the inverse of theradius to the fourth power. A typical graft diameter is 6 mm, so tocancel out a theoretical ⅓ reduction in resistance due to a shortenedlength of the graft, the diameter of the graft can be decreased to 5.4mm. The end result will be an equivalent resistance to flow considering:(a) Resistance∝Length, and (b) Resistance∝(1/Radius⁴).

An embodiment of the ported vascular access channel may include needlewells which are not on the top face of the device but rather on thesides. This configuration decreases the height of the implant in favorof a greater width and may be preferable in cachectic patients or thosewith little excess tissue in which to imbed the device.

An embodiment of the ported vascular access channel may contain a lumenwhich is not cylindrical in shape, but may instead be contoured as an“S” or “U” 16 (FIG. 9) or other configuration to optimize its interfacewith the patient's anatomy and the location of his or her vasculature.These alternative configurations may also serve to help vascularsurgeons tunnel the device under the skin to its optimal locationwithout causing kinks to form in the vessel.

Embodiment methods of coupling the top and bottom faces of the port toeach other include, but are not limited to, biocompatible plasticadhesives, interlocking teeth or snaps, ties, sutures, pegs, screws, orother fasteners. An embodiment comprises suture holes in the top andbottom port faces through which bioresorbable sutures may be stitched.This would approximate the top and bottom faces during the implantationsurgery and the period immediately following while the patient's naturaltissues started to adhere to and anchor the separate parts. As thistakes place, the resorbable sutures degrade and the top and bottom facesare no longer firmly fastened together. This allows the vessel withinthe port to retain its compliance, especially should the vessel laterneed another procedure such as balloon angioplasty. It also prevents theformation of an impenetrable junction between the top and bottom faces,which otherwise could be colonized by bacteria.

As described previously, an embodiment of the invention includes top andbottom faces which are not in direct association, instead leaving a gappresent between them. The end result of this configuration is improvedvessel compliance and a reduced risk of biofilm formation at thejuncture between the two faces of the port. For example, with FIG. 12portions 121 and 122 may not fully meet along surface 125 because, forexample, pegs 77 may be longer than their reciprocal female portions inpiece 121.

An embodiment of the device is a ported catheter (FIG. 10), which couldbe assembled as follows. A standard central line catheter 19 may featurea port system 20 comprising the port body as a single piece 16 ratherthan as a top and bottom face, needle well(s) 7, and bioactive matrixscaffold 8 as previously described.

Since it is often the case that dual-lumen central line catheters, withone lumen for withdrawing blood and one lumen for replacing it, become“blocked” by the suction they create as they withdraw blood, anembodiment alters the geometry of the catheter tubing to include threelumens. Two “withdrawal” lumens, in opposition to one another, poselittle or less risk of becoming blocked even if one lumen is suctionedto the wall of its vein. An embodiment may include a port with internalgeometry to accommodate such a catheter 19. In an embodiment, the distaltip of the central lumen may extend past the edge of the outer lumens sothat blood which is replaced through the central lumen re-enters thepatient's circulation downstream of the outer lumens, thereby minimizingthe amount of blood recirculated through the dialysis machine. Also,since subcutaneous implants incur a significant amount of tissueingrowth which may complicate their removal, the catheter may also beequipped with a “handle” which serves as a grasping point duringexplantation of the catheter.

An embodiment includes a method as follows. Following standard procedurefor inserting a central venous line into the patient's internal jugular,axillary/subclavian, or femoral veins, the head of the catheter, whichcomprises the port system as described previously, is tunneled beneaththe skin of the patient to remain in the subcutaneous tissue (FIG. 11)where it can be accessed periodically for fluid removal/injection.

In an embodiment an anchoring system (FIG. 6) may include a series ofrudders or keels 11 and suturing sites 12 which may be included in thebody of the port or other synthetic material, including a graft if oneis used, to stabilize and properly orient the port for puncture.Corrugated edges, a roughened outer surface, and the inclusion ofcollagen deposits or other tissue-promoting substances may encouragein-growth of tissue around the device and its anchors, furtherstabilizing it. It is well-known that porous materials demonstrateimproved tissue ingrowth and anchoring, and many surface-treatments havebeen described which also encourage this behavior.

Along the surface of the apparatus there may be angled “side-entrypoints” 3 (FIG. 5) that extend from the surface of the device to thelumen of the vessel. These side-entry points will allow a shallow entryinto the lumen of the graft and direct small guide wires or catheterswhich can be used to remove thrombi that form within the graft, afrequent and costly failure mode of vascular access grafts. Thisexpedites the physician's access into the graft, making for a quicker,simpler, and potentially less-costly procedure.

An embodiment of the ported vascular access channel may includeradiopaque markers fixed to the device to orient physicians and surgeonswho are implanting/revising/accessing the device for whatever reason.This is to enable healthcare providers to utilize radiographic imagingto identify appropriate sites for withdrawal/injection of fluid or tocorrectly locate the side-entry points, the channels through whichinterventional physicians may insert guide wires or catheters to removethrombi, as discussed previously.

An embodiment provides advantages that translate into a permanentvascular access system that will be usable shortly after implantation,retains its patency, is simple to use and maintain, requires lessintervention/revision, and is less prone to infection than otherprevious access methods. These features will have a positive impact onpatients who require hemodialysis, plasmapheresis, chemotherapy,parenteral nutrition, or any other condition requiring frequent bloodaccess.

While not specifically shown, and embodiment provides bioactivescaffolding surrounding the vessel (e.g., between vessel 4 and thesidewalls of shell components 6 of FIG. 4).

An embodiment includes a vascular port comprising: first and secondportions 44, 45 that are not monolithic with each other (FIG. 3). Forexample, portions 44, 45 may couple together along junction 31 in a“side-by-side” arrangement or along junction 30 in an “over-under”arrangement. The first portion includes a first arcuate surface 32(assuming an over-under arrangement) to contour to a first portion of avessel 34 and the second portion includes a second arcuate surface 33 tocontour to a second portion of the vessel. In other embodiments suchcontouring is not present.

The first and second portions couple to one another around the vesselwhen implanted to form a central chamber that houses the vessel. Acentral chamber is defined by element 46 in FIG. 5. In this picturevessel 4 is flush to the upper and lower walls of chamber 46 but thismay not be the case in all embodiments. In some embodiments there may bespace between the chamber walls and the vessel or there may be tissuescaffolding (e.g., a shape memory polymer foam or hydrogel) that snuglycouples the vessel to the walls of the chamber.

In FIG. 5 along cross-section 37″ the upper and lower portions 44′, 45′complete surround vessel 4 along a 360 degree perimeter. In otherembodiments upper and lower portions 44′, 45′ may still surround vessel4 but to a lesser extent than 360 degrees.

Returning to FIG. 3, the first portion includes a port that includes afunnel 35 with a funnel surface 18 that narrows as the funnel surfaceapproaches the central chamber. The central chamber includes a centrallongitudinal axis 36 (see also 36′ or 36″ of FIGS. 5 and 7 c) and thefunnel includes a central vertical axis 37 (see also 37′ of FIG. 5) thatis orthogonal to the longitudinal axis. The second portion includes ahardened, non-compliant surface 9 that intersects the vertical axis 37′.This helps prevent through-and-through punctures of vessel 4.

In an embodiment the funnel includes a length 38 that is parallel to thecentral longitudinal axis and a width 39 that is orthogonal to thecentral longitudinal axis; and the length is greater than the width. Forexample, FIG. 3 illustrates an oblong funnel whereas FIG. 4 illustratescircular funnels. The use of the oblong funnel illustrates a funnel“configured to” simultaneously accommodate both blood intake and bloodreturn penetration members. For example, see FIG. 16. Because funnel 35is largely orthogonal to the vessel 34 and has appropriate length 38 twoopposing needles 60, 61 are accommodated. This is in contrast to systemswhere the funnel forms an acute angel with longitudinal axis 36 suchthat the needle in the funnel is largely directed either upstream ordownstream to flow in a vessel. FIG. 16 shows two needles collectivelypositioned upstream and downstream to a vessel.

In an embodiment the funnel includes a tissue scaffold thatsubstantially fills the funnel. For example, see element 8 of FIG. 4.However, in other embodiments the matrix or scaffold may not fill thefunnel but merely occupy some space within the funnel. This would be thecase when scaffold of 88 (FIG. 14) is inserted into chamber 124 (FIG.13) of upper portion 121′ (or into chamber 124′ of upper piece 121 ofFIG. 12).

In an embodiment the tissue scaffold includes one or more of a foam, apolyurethane foam, a hydrogel, poly ethylene glycol (PEG), polyglycolicacid (PGA), polylactic acid (PLA), poly(lactic-co-glycolic acid) (PLGA),glutaraldehyde adhesives, fibrin sealants, cyanoacrylates, collagenouscompounds, electrospun fabrics, and decellularized extracellular matrix.In an embodiment an adhesive (e.g., cyanoacrylate glue) couples thetissue scaffold to the funnel surface 18.

In an embodiment outer surfaces 40, 41 of the first and second portions44, 45 are porous or are finished in any manner that promotes tissueingrowth (e.g., roughened, corrugated). In an embodiment, inner surfacesof the first and second portions 44, 45 (e.g., surfaces of the first andsecond portions which come into contact with the vessel), in addition toor instead of outer surfaces of the first and second portions 44, 45,are porous or are finished in any manner that promotes tissue ingrowth(e.g., roughened, corrugated). Such inner surfaces may include, forexample, area 6 of FIG. 4.

An embodiment comprises a tissue scaffold included within a subportionof the first portion, and the subportion is between the central chamberand a proximal opening of the funnel. For example, see portion 47 ofFIG. 12. Subportion 47 may include slot 124′ but in other embodimentsthere may be no such slot and the scaffold may provide a resistive fitbetween the vessel and upper portion 121.

Embodiments described herein provide the first and second portions areconfigured to fixedly couple to each other but not to the vessel. Forexample, with FIG. 12 portion 122 includes a male member 77 and portion121 includes a female member 78 to receive the male member and couplethe first and second portions to each other. In doing so, portion 121may couple flush to surface 125 but in other embodiments may not do so.Further, while portions 121, 122 couple to one another “fixedly” (e.g.,using male/female coupling) those portions may only couple to the vesselwith a resistive fit. That resistive fit may be due to a cell scaffoldbetween the vessel and portions 121, 122 or the portions 121, 122 may besized such that the central chamber they provide may provide aresistance fit with the vessel. Further, no portion of the port needs tobe sutured to the vessel. This may avoid damage to the vessel and/orallow for future size changes to the vessel. For example, the port maycouple to a fistula soon after fistula formation and before full fistulamaturation. Further, this may accommodate future balloon angioplasty ofthe vessel.

Regarding coupling the port to vessel, in an embodiment the first andsecond portions rotationally and slideably couple to the vessel whenimplanted. For example, in FIG. 3 portions 44, 45 may rotate 53 aboutaxis 36 and/or slide parallel to axis 36 considering they may only havea resistance fit with vessel 34 instead of being sutured thereto.

In an embodiment, portions may be sutured together. For example, in FIG.12 suture in channels 49, 50 may couple pieces 121, 122 together. Thesuture may be in addition to or instead of members 77, 78. The suturesmay be biodegradable such to accommodate future vessel expansion. Inother words, in an embodiment the first and second portions includeouter surfaces having channels 49, 50 that align with one another whenthe first and second portions couple to each other.

In an embodiment the coupling mechanism between portions may alsofixedly couple a cellular scaffold to the portions. For example, withFIG. 12 male member 77 intersects a subportion 124′ of the first portion121 when coupled to the female member 78. When scaffold 88 (FIG. 14) isin slot 124′ the male member would hold scaffold 88 in place.

In an embodiment an additional tissue scaffold may be included within anadditional subportion of the second portion (e.g., portion 48 of portion122 of FIG. 12), and the additional subportion is between the centralchamber and wall of the second portion.

In an embodiment, the central chamber 46 forms a conduit that receivesthe vessel (see FIG. 5).

In an embodiment the first portion includes an additional port 2′ (FIG.2) that includes an additional funnel with an additional funnel surfacethat narrows as the additional funnel surface approaches the centralchamber; the additional funnel includes an additional central verticalaxis that is orthogonal to the longitudinal axis; and the hardened,non-compliant surface that intersects the additional vertical axis.

In an embodiment, the funnel surface 18 includes: (a) a distal wallsurface 51 that slopes proximally as the distal surface approaches thecentral chamber, and (b) a proximal wall surface 52 that slopes distallyas the proximal surface approaches the central chamber (FIG. 3).

In an embodiment, the funnel surface 18 is treated to promote tissueingrowth. In an embodiment the funnel surface includes an attachmentsurface selected form the group comprising: a porous surface, a dimpledsurface, and a tissue scaffold adhered to the attachment surface.

In an embodiment (FIG. 5), the first portion 44′ includes first andsecond ports 3, 3′ separate from the port 8, and the first port includesa first central axis 55 forming an acute angle 56 with the centrallongitudinal axis 36′ of the central chamber and the second portincludes a second central axis 54 forming an obtuse angle 57 with thecentral longitudinal access of the central chamber.

More examples now follow.

Example 1 includes a vascular port comprising: first and second portionsthat are not monolithic with each other; wherein: (a)(i) the firstportion includes a first arcuate surface to contour to a first portionof a vessel and the second portion includes a second arcuate surface tocontour to a second portion of the vessel; (a)(ii) the first and secondportions couple to one another around the vessel when implanted to forma central chamber that houses the vessel; (a)(iii) the first portionincludes a port that includes a funnel with a funnel surface thatnarrows as the funnel surface approaches the central chamber; (a)(iv)the central chamber includes a central longitudinal axis and the funnelincludes a central vertical axis that is orthogonal to the longitudinalaxis; (a)(v) the second portion includes a hardened, non-compliantsurface that intersects the vertical axis.

The first and second portions may be top and bottom portions or may bothbe side portions in various embodiments.

Example 2 includes the port of 1 wherein: the funnel includes a lengththat is parallel to the central longitudinal axis and a width that isorthogonal to the central longitudinal axis; and the length is greaterthan the width.

Example 3 includes the port of example 1 wherein the funnel includes atissue scaffold that substantially fills the funnel.

Example 4 includes the port of example 1, wherein the tissue scaffoldincludes a member selected from the group comprising: a foam, apolyurethane foam, a hydrogel, poly ethylene glycol (PEG), polyglycolicacid (PGA), polylactic acid (PLA), poly(lactic-co-glycolic acid) (PLGA),glutaraldehyde adhesives, fibrin sealants, cyanoacrylates, collagenouscompounds, electrospun fabrics, and decellularized extracellular matrix.

Example 5 includes the port of example 1 comprising an adhesive thatcouples the tissue scaffold to the funnel surface.

Example 6 includes the port of example 1, wherein outer surfaces of thefirst and second portions are porous.

Another version of Example 6 includes the port of example 1, wherein anysurfaces of the first and second portions are porous.

For instance, in addition to or instead of outer surfaces of the firstand second portions, the inner surfaces of the device may also haveporous portions (e.g., along the central axis) in order to promotetissue attachment. Such inner surfaces may include, for example, area 6of FIG. 4.

Example 7 includes the port of example 1 comprising a tissue scaffoldincluded within a subportion of the first portion, and the subportion isbetween the central chamber and a proximal opening of the funnel.

Example 8 includes the port of example 7 wherein at least one of thefirst and second portions includes a male member and another of thefirst and second portions includes a female member to receive the malemember and couple the first and second portions to each other.

Example 9 includes the port of example 8, wherein the male memberintersects the subportion of the first portion when coupled to thefemale member.

Example 10 includes the port of example 7 comprising an additionaltissue scaffold included within an additional subportion of the secondportion, and the additional subportion is between the central chamberand wall of the second portion.

Example 11 includes the port of example 1 wherein the central chamberforms a conduit that receives the vessel.

Example 12 includes the port of example 1, wherein: (a)(i) the firstportion includes an additional port that includes an additional funnelwith an additional funnel surface that narrows as the additional funnelsurface approaches the central chamber; (a)(iv) the additional funnelincludes an additional central vertical axis that is orthogonal to thelongitudinal axis; (a)(v) the hardened, non-compliant surface thatintersects the additional vertical axis.

Example 13 includes the port of example 1, wherein the first and secondportions include outer surfaces having channels that align with oneanother when the first and second portions couple to each other.

Example 14 includes the port of example 1, wherein the first and secondportions are configured to fixedly couple to each other but not to thevessel.

Example 15 includes the port of example 1, wherein the funnel surfaceincludes: (a) a distal wall surface that slopes proximally as the distalsurface approaches the central chamber, and (b) a proximal wall surfacethat slopes distally as the proximal surface approaches the centralchamber.

Example 16 includes the port of example 1, wherein the funnel surface istreated to promote tissue in growth.

Example 17 includes the port of example 16, wherein the funnel surfaceincludes an attachment surface selected from the group comprising: aporous surface, a dimpled surface, and a tissue scaffold adhered to theattachment surface.

Example 18 includes the port of example 1, wherein the funnel isconfigured to simultaneously accommodate both blood intake and bloodreturn penetration members.

Example 19 includes the port of example 1, wherein the first and secondportions rotationally and slideably couple to the vessel when implanted.

Example 20 includes the port of example 1, wherein the first and secondportions couple to one another via at least one biodegradable coupler.

Example 21 includes the port of example 20, wherein the biodegradablecoupler includes suture.

Example 22 includes the port of example 1, wherein the first and secondportions couple to one another around the vessel and collectively coupleto the vessel via a resistance fit and the first and second portions arenot configured to couple to the vessel via sutures.

Example 23 includes the port of example 1, wherein the first portionincludes first and second ports separate from the port, and the firstport includes a first central axis forming an acute angle with thecentral longitudinal access of the central chamber and the second portincludes a second central axis forming an obtuse angle with the centrallongitudinal axis of the central chamber.

Example 24 includes an apparatus comprising: first and second portionsthat are monolithic with each other; and a vessel; wherein: (a)(i) thefirst portion includes a first arcuate surface to contour to a firstportion of the vessel and the second portion includes a second arcuatesurface to contour to a second portion of the vessel; (a)(ii) the firstand second portions couple to one another around the vessel to form acentral chamber that houses the vessel; (a)(iii) the first portionincludes a port that includes a funnel with a funnel surface thatnarrows as the funnel surface approaches the central chamber; (a)(iv)the central chamber includes a central longitudinal axis and the funnelincludes a central vertical axis that is orthogonal to the longitudinalaxis; (a)(v) the second portion includes a hardened, non-compliantsurface that intersects the vertical axis.

Some embodiments may ship to a medical facility with a graft or catheteralready coupled to the port device and/or the port device may later becoupled to such a graft or cathether.

While a “needle” is addressed periodically herein embodiments may workwith access devices in general that permit access and transportation offluid. Such embodiments include conduits of 14 to 20 gauge for example.Also, a “vessel” as used herein may be tissue or synthetic vessel,catheter, and/or graft and the like.

An embodiment includes a kit including various ports wherein the sizeand/or shape (FIG. 1 vs. FIG. 9) of the central chamber of the ports maychange to accommodate varying anatomical features. An embodimentincludes a funnel that does not narrow but instead is a mere conduit forguiding a needle to a vessel.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art will appreciate numerousmodifications and variations therefrom. It is intended that the appendedclaims cover all such modifications and variations as fall within thetrue spirit and scope of this present invention.

What is claimed is:
 1. A vascular port comprising: a top portion; and abottom portion, wherein: the top portion and the bottom portion are notmonolithic with each other; the top portion includes a first body havinga first interior arcuate surface configured to contour to a top portionof a vessel and a first outer surface configured to face away from thevessel when implanted; the bottom portion includes a second body havinga second interior arcuate surface configured to contour to a bottomportion of the vessel; the top and bottom portions configured to coupleto one another around the vessel when implanted to form a centralchamber that houses the vessel with the first interior arcuate surfacefacing the second interior arcuate surface; the first outer surfacefully encloses a central opening in the first body of the top portionthat allows a needle to pass through; the central chamber includes acentral longitudinal axis and the central opening includes a centralvertical axis that is orthogonal to the central longitudinal axis; thesecond interior arcuate surface of the second body of the bottom portionis a hardened, non-compliant surface; and the second interior arcuatesurface of the second body of the bottom portion intersects the centralvertical axis when the top and bottom portions are coupled to oneanother.
 2. The port of claim 1, wherein the first outer surfaces of thetop portion and an outer surface of the bottom portion is porous.
 3. Theport of claim 1, wherein the first outer surface of the top portion andan outer surface of the bottom. portion having channels that areconfigured to align with one another when the top and bottom portionscouple to each other.
 4. The port of claim 1, wherein the top portionfurther includes a funnel extending from the central opening, whereinthe funnel has a funnel surface that slopes towards a center of thecentral opening as the funnel surface approaches the central chamber. 5.The port of claim 1, wherein the top portion further includes a funnelextending from the central opening of the top portion, wherein thefunnel is configured to simultaneously accommodate both blood intake andblood return penetration members.
 6. The port of claim 1, wherein thetop and bottom portions are configured to rotationally and slidablycouple to the vessel when implanted.
 7. The port of claim 1, wherein thetop and bottom portions are configured to couple to one another aroundthe vessel and collectively couple to the vessel via a resistance fitand the top and bottom portions are not configured to couple to thevessel via sutures.
 8. The port of claim 1, wherein the top portionfurther includes first and second passages separate from the centralopening, and the first passage includes a first central axis forming anacute angle with the central longitudinal axis of the central chamberand the second passage includes a second central axis forming an obtuseangle with the central longitudinal axis of the central chamber.
 9. Theport of claim 1, wherein outer surfaces of the top and bottom portionsare roughened.
 10. The port of claim 1, wherein the first interiorarcuate surface of the top portion and the second interior arcuatesurface of the bottom portion are contoured to minimize impact on thevessel.
 11. A method of using the port of claim 1, comprising:inserting, through the central opening in the top portion of the port, afirst needle in the vessel; inserting, through the central opening inthe top portion of the port, a second needle in the vessel; withdrawingblood, via the first needle, from within the vessel; and returning theblood, via the second needle, to the vessel, wherein the second needleis placed upstream of the first needle in the vessel.
 12. The port ofclaim 1, further comprising a tissue scaffold included within asubportion of the top portion, wherein the subportion is between thecentral chamber and the central opening of the top portion.
 13. The portof claim 12, further comprising an additional tissue scaffold includedwithin an additional subportion of the second portion, wherein theadditional subportion is between the central chamber and a wall of thebottom portion.
 14. The port of claim 1, wherein at least one of the topand bottom portions includes a male member and another of the top andbottom portions includes a female member configured to receive the malemember and couple the top and bottom portions to each other.
 15. Theport of claim 14, wherein the male member is configured to intersect asubportion of the top portion when coupled to the female member.
 16. Theport of claim 1, wherein the top portion further includes a funnelextending from the central opening, wherein the funnel has a funnelsurface that is treated to promote tissue ingrowth.
 17. The port ofclaim 16, wherein the funnel surface includes an attachment surfaceselected from the group comprising: a porous surface, a dimpled surface,and a tissue scaffold adhered to the attachment surface.
 18. The port ofclaim 1, wherein the top and bottom portions are configured to couple toone another via at least one biodegradable coupler.
 19. The port ofclaim 18, wherein the at least one biodegradable coupler includes asuture.
 20. The port of claim 1, wherein: the top portion furthercomprises a funnel extending towards the central chamber from thecentral opening of the top portion.
 21. The port of claim 20, furthercomprising a tissue scaffold that is configured to substantially fillsthe funnel.
 22. The port of claim 21, wherein the tissue scaffoldincludes a member selected from the group comprising: a foam, apolyurethane foam, a hydrogel, poly ethylene glycol (PEG), polyglycolicacid (PGA), polylactic acid (PLA), poly(lactic-co-glycolic acid) (PLGA),glutaraldehyde adhesives, fibrin sealants, cyanoacrylates, collagenouscompounds, electro spun fabrics, and decellularized extracellularmatrix.
 23. The port of claim 21, wherein the funnel includes a funnelsurface comprising an adhesive that is configured to couple the tissuescaffold to the funnel surface.
 24. A vascular port comprising: a topportion; and a bottom portion, wherein: the top portion and the bottomportion are not monolithic with each other; the top and bottom portionsconfigured to couple to one another around a vessel when implanted toform a central chamber that houses the vessel between a first surface ofthe top portion and a second surface of the bottom portion; the topportion includes an opening that allows a needle to pass through and afunnel extending towards the central chamber from the opening; thecentral chamber includes a central longitudinal axis and the openingincludes a central vertical axis that is orthogonal to the centrallongitudinal axis; and the second surface of the bottom portion is ahardened, non-compliant surface that extends through the centralvertical axis when the top and bottom portion are coupled to oneanother.
 25. The port of claim 24, wherein outer surfaces of the top andbottom portions are porous.
 26. The port of claim 24, wherein thecentral chamber forms a conduit that receives the vessel.
 27. The portof claim 24, wherein: wherein the funnel has a funnel surface thatnarrows as the funnel surface approaches the central chamber, thecentral vertical axis being included within the funnel; the top portionfurther includes an additional opening and an additional funnel with anadditional funnel surface that narrows as the additional funnel surfaceapproaches the central chamber; and the additional funnel includes anadditional central vertical axis that is orthogonal to the centrallongitudinal axis.
 28. The port of claim 24, wherein the top and bottomportions include outer surfaces having channels that are configured toalign with one another when the top and bottom portions couple to eachother.
 29. The port of claim 24, wherein the funnel has a funnel surfacethat slopes towards a center of the opening as the funnel surfaceapproaches the vessel.
 30. The port of claim 24, wherein the funnel isconfigured to simultaneously accommodate both blood intake and bloodreturn penetration members.
 31. The port of claim 24, wherein the topand bottom portions are configured to rotationally and slidably coupleto the vessel when implanted.
 32. The port of claim 24, wherein the topand bottom portions are configured to couple to one another via at leastone biodegradable coupler.
 33. The port of claim 32, wherein the atleast one biodegradable coupler includes a suture.
 34. The port of claim24, wherein the top and bottom portions are configured to couple to oneanother around the vessel and collectively couple to the vessel via aresistance fit and the top and bottom portions are not configured tocouple to the vessel via sutures.
 35. The port of claim 24, wherein thetop portion further includes first and second passages separate from theopening, and the first passage includes a first central axis forming anacute angle with the central longitudinal axis of the central chamberand the second passage includes a second central axis forming an obtuseangle with the central longitudinal axis of the central chamber.
 36. Theport of claim 24, wherein outer surfaces of the top and bottom portionsare roughened.
 37. The port of claim 24, wherein the top portionincludes a first arcuate surface and the bottom portion includes asecond arcuate surface, wherein the first arcuate surface of the topportion and the second arcuate surface of the bottom portion arecontoured to minimize impact on the vessel.
 38. A method of using theport of claim 24, comprising: inserting, through the opening in the topportion of the port, a first needle in the vessel; inserting, throughthe opening in the top portion of the port, a second needle in thevessel; withdrawing blood, via the first needle, from within the vessel;and returning the blood, via the second needle, to the vessel, whereinthe second needle is placed upstream of the first needle in the vessel.39. The port of claim 24, wherein the funnel has a funnel surface thatis treated to promote tissue ingrowth.
 40. The port of claim 39, whereinthe funnel surface includes an attachment surface selected from thegroup comprising: a porous surface, a dimpled surface, and a tissuescaffold adhered to the attachment surface.
 41. The port of claim 24,further comprising a tissue scaffold included within a subportion of thetop portion, wherein the subportion is between the central chamber andthe opening of the top portion.
 42. The port of claim 41, furthercomprising an additional tissue scaffold included within an additionalsubportion of the bottom portion, wherein the additional subportion isbetween the central chamber and a wall of the bottom portion.
 43. Theport of claim 24, wherein at least one of the top and bottom portionsincludes a male member and another of the top and bottom portionsincludes a female member that is configured to receive the male memberand couple the top and bottom portions to each other.
 44. The port ofclaim 43, wherein the male member is configured to intersect asubportion of the top portion when coupled to the female member.
 45. Theport of claim 24, further comprising a tissue scaffold that isconfigured to substantially fills the funnel.
 46. The port of claim 45,wherein the tissue scaffold includes a member selected from the groupcomprising: a foam, a polyurethane foam, a hydrogel, poly ethyleneglycol (PEG), polyglycolic acid (PGA), polylactic acid (PLA),poly(lactic-co-glycolic acid) (PLGA), glutaraldehyde adhesives, fibrinsealants, cyanoacrylates, collagenous compounds, electrospun fabrics,and decellularized extracellular matrix.
 47. The port of claim 45,wherein the funnel includes a funnel surface comprising an adhesive thatis configured to couple the tissue scaffold to the funnel surface.